A piezoelectric device is a device including a piezoelectric element and is applied to various apparatus, a sensor, and the like. For example, in a liquid ejecting apparatus, various liquids are ejected from a liquid ejecting head by using the piezoelectric device. As the liquid ejecting apparatus, for example, there is an image recording apparatus such as an ink jet type printer or an ink jet type plotter and, in recent years, the liquid ejecting apparatus has been also applied to various manufacturing apparatuses by taking advantage of the fact that a very small amount of a liquid can be accurately landed in a predetermined position. For example, the liquid ejecting apparatus is applied to a display manufacturing apparatus for manufacturing a color filter such as a liquid crystal display, an electrode forming apparatus for forming an electrode of an organic electro luminescence (EL) display, a field emission display (FED), and the like, and a chip manufacturing apparatus for manufacturing a bio-chip (biochemical element). Then, a recording head for the image recording apparatus ejects a liquid ink and a color material ejecting head for the display manufacturing apparatus ejects a solution of each color material of Red (R), Green (G), and Blue (B). Furthermore, in an electrode material ejecting head for the electrode forming apparatus, a liquid electrode material is ejected and in a bio-organic material ejecting head for the chip manufacturing apparatus, a solution of a bio-organic material is ejected.
The liquid ejecting head described above is configured by laminating a nozzle plate on which a plurality of nozzles are formed, a pressure chamber forming substrate in which a pressure chamber corresponding to each nozzle is formed, a piezoelectric element (a type of actuator) causing a pressure variation in a liquid within each pressure chamber, a sealing plate in which a concave section accommodating the piezoelectric element is formed, and the like. Then, the liquid ejecting head is configured to eject the liquid from the nozzle by using the pressure variation by causing the pressure variation (pressure change) in the liquid within the pressure chamber by supplying a driving signal to the piezoelectric element. Here, a technique for forming a driving circuit (also referred to as driver circuit) for transmitting a driving signal to each piezoelectric element on a surface facing the piezoelectric element within the concave section of the sealing plate has been developed (for example, see PTL 1). A bump electrode for electrically connecting the driving circuit and the piezoelectric element is formed on a surface on which the driving circuit is formed. Moreover, as the sealing plate, since the driving circuit can be created by a semiconductor process (that is, a film forming step, a photolithography step, an etching step, and the like), a substrate (hereinafter, referred to as a silicon substrate) made of silicon is used.